Finding Feature Information

Your software release may not support all the features documented in this module. For the latest feature information and caveats, see the release notes for your platform and software release. To find information about the features documented in this module, and to see a list of the releases in which each feature is supported, see the Feature Information Table at the end of this document.

Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to http:/​/​www.cisco.com/​go/​cfn. An account on Cisco.com is not required.

Prerequisites for 802.11w

To configure 802.11w feature for optional and mandatory, you must have WPA and AKM configured.

Note

The RNS (Robust Secure Network) IE must be enabled with an AES Cipher.

To configure 802.11w as mandatory, you must enable PMF AKM in addition to WPA AKM.

Information About 802.11w

Wi-Fi is a broadcast medium that enables any device to eavesdrop and participate either as a legitimate or rogue device. Control and management frames such as authentication/deauthentication, association/disassociation, beacons, and probes are used by wireless clients to select an AP and to initiate a session for network services.

Unlike data traffic which can be encrypted to provide a level of confidentiality, these frames must be heard and understood by all clients and therefore must be transmitted as open or unencrypted. While these frames cannot be encrypted, they must be protected from forgery to protect the wireless medium from attacks. For example, an attacker could spoof management frames from an AP to tear down a session between a client and AP.

The 802.11w protocol applies only to a set of robust management frames that are protected by the Management Frame Protection (PMF) service. These include Disassociation, Deauthentication, and Robust Action frames.

Management frames that are considered as robust action and therefore protected are the following:

Spectrum Management

QoS

Block Ack

SA Query

Vendor-specific Protected

When 802.11w is implemented in the wireless medium, the following occur:

Client protection is added by the AP adding cryptographic protection (by including the MIC information element) to deauthentication and disassociation frames preventing them from being spoofed in a DOS attack.

Infrastructure protection is added by adding a Security Association (SA) teardown protection mechanism consisting of an Association Comeback Time and an SA-Query procedure preventing spoofed association request from disconnecting an already connected client.

association-comeback—Configures the 802.11w association comeback time. The range is from 1 to 20 seconds.

mandatory—Requires clients to negotiate 802.11w PMF protection on a WLAN.

optional—Enables 802.11w PMF protection on a WLAN.

saquery—Time interval identified in milliseconds before which the SA query response is expected. If the switch does not get a response, another SQ query is tried. The range is from 100 to 500 ms. The value must be specified in multiples of 100 milliseconds.

Step 5

no shutdown

Example:

Switchno shutdown

Restart the WLAN for the changes to take effect.

Step 6

end

Example:

Switch(config-wlan)# end

Returns to privileged EXEC mode. Alternatively, you can also press Ctrl-z to exit global configuration mode.

mandatory—Disables clients to negotiate 802.11w PMF protection on a WLAN.

optional—Disables 802.11w PMF protection on a WLAN.

saquery—Time interval identified in the association response to an already associated client before the association can be tried again. This time interval checks if the client is a real client and not a rogue client during the association comeback time. If the client does not respond within this time, the client association is deleted from the switch The range is from 100 to 500 ms. The value must be specified in multiples of 100 milliseconds.

Step 5

no shutdown

Example:

Switchno shutdown

Restart the WLAN for the changes to take effect.

Step 6

end

Example:

Switch(config-wlan)# end

Returns to privileged EXEC mode. Alternatively, you can also press Ctrl-z to exit global configuration mode.

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